The first three words.

The regularly reported influence on stuttering of early sentence position, particularly the first three words, evidently is confounded with the influence of grammatical class, another variable consistently found to correlate with stuttering frequency. Representative samples of English prose are found to contain, in early sentence positions, words of grammatical classes known to be associated with high stuttering frequency. Use of a specially constructed passage, which markedly altered the grammatical class composition of the first three words of sentences, resulted in significant changes in the typical patterns of stuttering frequency associated with word position and grammatical class. The findings lead to an analysis which identifies linguistics stress as the essential feature responsible for the effect on stuttering of both grammatical class and sentence position.